掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Emerging infectious diseases, cancer, and other diseases are quickly tested mainly via immune reactions based on specific molecular recognition between antigens and antibodies. By changing the diameter of solid-state pores, biomolecules of various sizes can be rapidly detected at the single-molecule level. The combination of immunoreactions and solid-state pores paves the way for an efficient testing method with high specificity and sensitivity. The challenge in developing this method is achieving quantitative analysis using solid-state pores. Here, we demonstrate a method with a low limit of detection for testing tumor markers using a combination of immunoreactions and solid-state pore technology. Quantitative analysis of the mixing ratio of two and three beads with different diameters was achieved with an error rate of up to 4.7%. The hybrid solid-state pore and immunoreaction methods with prostate-specific antigen (PSA) and anti-PSA antibody-modified beads achieved a detection limit of 24.9 fM PSA in 30 min. The hybrid solid-state pore and immunoreaction enabled the rapid development of easy-to-use tests with lower limit of detection and greater throughput than commercially available immunoassay for point-of-care testing.

DOI： 10.1038/s41598-024-67112-8

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その他リンク： https://www.nature.com/articles/s41598-024-67112-8

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Chemical Society (ACS)  

DOI： 10.1021/acsnano.4c01989

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

Abstract

Slowing down translocation dynamics is a crucial challenge in nanopore sensing of small molecules and particles. Here, it is reported on nanoparticle motion‐mediated local viscosity enhancement of water‐organic mixtures in a nanofluidic channel that enables slow translocation speed, enhanced capture efficiency, and improved signal‐to‐noise ratio by transmembrane voltage control. It is found that higher detection rates of nanoparticles under larger electrophoretic voltage in the highly viscous solvents. Meanwhile, the strongly pulled particles distort the liquid in the pore at high shear rates over 10³ s⁻¹ which leads to a counterintuitive phenomenon of slower translocation speed under higher voltage via the induced dilatant viscosity behavior. This mechanism is demonstrated as feasible with a variety of organic molecules, including glycerol, xanthan gum, and polyethylene glycol. The present findings can be useful in resistive pulse analyses of nanoscale objects such as viruses and proteins by allowing a simple and effective way for translocation slowdown, improved detection throughput, and enhanced signal‐to‐noise ratio.

DOI： 10.1002/smtd.202301523

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

Abstract

Artificial nanofluidic networks are emerging systems for blue energy conversion that leverages surface charge‐derived permselectivity to induce voltage from diffusive ion transport under salinity difference. Here the pivotal significance of electrostatic inter‐channel couplings in multi‐nanopore membranes, which impose constraints on porosity and subsequently influence the generation of large osmotic power outputs, is illustrated. Constructive interference is observed between two 20 nm nanopores of 30 nm spacing that renders enhanced permselectivity to osmotic power output via the recovered electroneutrality. On contrary, the interference is revealed as destructive in two‐dimensional arrays causing significant deteriorations of the ion selectivity even for the nanopores sparsely distributed at an order of magnitude larger spacing than the Dukhin length. Most importantly, a scaling law is provided for deducing the maximal membrane area and porosity to avoid the selectivity loss via the inter‐pore electrostatic coupling. As the electric crosstalk is inevitable in any fluidic network, the present findings can be a useful guide to design nanoporous membranes for scalable osmotic power generations.

DOI： 10.1002/exp.20220110

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER  

Nanopore is an emerging energy-harvesting device that can create electricity directly from salt solutions. Here, we present a protocol for the preparation and structure optimization of solid-state multipore osmotic power generators. We describe steps for sculpting multiple pores at well-defined positions in a thin SiNx membrane using electron-beam lithography. We also detail an imprinting technique to form polydimethylsiloxane blocks with fluidic channels bonded to the multipore membrane. This approach facilitates repeated liquid exchange processes involved in ionic current measurements.For complete details on the use and execution of this protocol, please refer to Tsutsui et al.1

DOI： 10.1016/j.xpro.2023.102227

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